Metal-plated article.



E. L. WATROUS.

METAL PLATED ARTICLE.

APPLICATION FILED nus, 1909.

1,027,782. Patented May 28, 19 2.

' UNITED STATES PATENT 1 mm.

EDWARD L. 'w'n'mous, or nEs momnsrown, AssIeNon 'ro E'. L. wnrnous' onpvnmzme comrnmz, A conronn'rron or sourn'nnxo'rn'.

METAL-PLATED ARTICLE.

Specification of Letters Patent.

Patented May 28,1912.

Application filed Kay 8, 1909. Serial No. 493,585.

To all whom it may concern:

Be it known'that I, EDWARD L. WATRoUs, a citizen of the United States, residing at Des Moines, in the county of Polk and State fof Iowa, have invented a certain new and useful Metal-Plated Article, of which the following is a specification.

The object of my invention is .to provide an article of manufacture such for instance as a bolt and nut with a body portion made of ametal such as iron which is liable to rust and corrode with a plating or coating of a material such as zinc in whichthe inner layer of the plating or coating is formed integral ,or made homogeneous with the body and the outer portion of the layer is made to conform exactly in outline with the,

surface of the'body'portion before the layer was applied, so that the finished article will 2 shows an enlarged, detail sectional view illustrating a small portion of the body of througha part of the bolt, and Fig. 3 shows a detail sectional view greatly magnified the article with the coating or plating material thereon. V

Referring to the accompanying drawings, I have used the reference numeral 10 to indicate the body portion of the bolt, 11 the screw-threaded portion thereof; 12 the nut, and 13 the screw-threaded portion thereof. On the surface of both the bolt and nut is a layer 14 of plating material such as zinc.

In the construction of the article, the threads arefirst out upon the bolt and nut in the ordinary way and then the bolt and nut-are both placed in the bath containing melted'zinc or other plating material, and then both are subjected to a rapid centrifugal action to thereby throw off all superfluous plating material and to leave the outer surface of the plating material of exactly the same shape as the outer sur face of the article to which theplating is. applied so that, in the screw-threaded portions thereof, the plating material will be just as thick on one part of the screw-thread as another. This process of metal plating forms the subject-matter of my co-pending application, Serial Number 1 93,584, filed May 3, 1909. The article thus formed comprises a bolt and a nut made of metal such as iron having a coating thereon which is formed integral with and made homogeneous with the bolt and nut That is to say,

the layerof plating or coating material is extended into the small pores or crevices between the particles of which the article is formed and therefore the under surface of.

the layer of plating or coating material is rough and irregular, while the outer surface conforms accurately to the general outlines of the surface of the article, and the outer layer of the coating or plating material is made to conform exactly in outline with the general outline of the article to which the coating or plating is applied.

Heretofore, it has been found commercially impracticable to provide a zinc plating or coating for bolts and nuts for the reason that the plating .or coating thus applied was usually irregular in contour and did not conform exactly with the general contour of the article to which it was applied, the coating or plating material being usually much heavier or thicker in the grooves between the threads than on the outer surfaces of the threads themselves. I have discovered that by first placing an article of this kind in melted zinc and then subjecting the parts of the article to rapid centrifugal action I while it isstill heated, I can produce a layer of coating material that is irregular in outline on its inner surface to permeate the pores or crevices of the article and that is smooth on its outer surface, and its outer surface will conform exactly with the general contour of the outer. surface of the" thread portions of. the article. a I am aware also that articles of this cla have been treated to an electro-plating process which, however, is distin my invention in that the e ectro-plating process deposits the plating or coating material in an exactly uniform manner over the exposed outer surface of the article and that the inner portion of the layer of plat ing or coating material does not, to any ma-' ished from terial' extent, enter the pores or crevices, nor does it become integral or homogeneous therewith, and when used for such purposes as on the threads of a bolt and nut, the layer is likely to come off in flakes or scales and leave the body portion in the same condit-ion as it was before the coating orlayer was applied.- In my improved article, this is impossible for the reason that the layer of coating or plating material is integral or homogeneous with the surface of the article and, even if the greater portion of the layer were removed by means such, for instance, as a file, there would still be a considerable quantity of the zinc so thoroughly united with the metal as to prevent corrosion or rust. It is obvious, therefore, that an article of this kind, if treated to the well known process of dipping it in melted zinc or if provided with a coating or layer by the electro plating process would be radically diflerent from my present invention because if either of these well-known processes is used, the article cannot be provided with a coating or layer formed integral or homogeneous with the metal and being of uniform thickness throughout conforming exactly in contour with the general contour of the surface of the article to which the coating is applied. I claim as my invention.

As a new article of manufacture, an iron body initially formed with screw threads and provided with a coating ofzinc, the inncr portion of said coating permeating the pores and crevices of the article and being homogeneous therewith and thereby resisting removal by sealing or flaking, this coating having been formed by immersion of the article in molten zinc and there heating until the pores open and the molten metal enters and becomes homogeneous with the surface metal of the article, said coated article being then removed and subjected While hot to rapid rotation, whereby centrifugal action removes all excess of the molten coating, leaving the outer surface of the plating material conforming substantially in shape and position with the surface of the article to which the plating was applied, said plating. being rooted or blended with the underlymg iron and characterized by a surface smoother than that produced by simple dipping, said plating being just as thick on one part of the threaded article as on another, whereby the fit of the plated screw-threads in another article will still be accurate. Des Moines, Iowa, April 10, 1909.

EDWARD L. WATROUS. Witnesses:

M. B. GOLDIZEN, N. M. TAYLOR. 

